Researchers want to study how dairy consumption affects colon cancer. They randomly selected a group of 10,000 people and assigned them by randomization into either a group that consumes dairy or a group that does not consume dairy during the study period. The participants are studied for a period of 10 years.

a. What is the exposure?

b. What is the outcome?

c. Is this study an observational study or an experimental study? Explain.